Field of the Invention
The invention relates to a prismatic joint having a number of prisms which are arranged such that they can rotate with respect to one another, for an optical swiveling device. In particular, the aim of the prismatic joint is to allow the optical path of a recording and projection appliance to be positioned within a large solid angle range, such that a comparatively small part of the solid angle range can be recorded, and projection is made possible within this small part.
A prismatic joint or prism joint such as this can be used for a very wide range of purposes in optical swiveling devices. For example, the prismatic joint can be used in a swiveling device in order to create architectural records, for example of the interiors of churches or the like, or for cartographic recording of large areas by laser range finding, as well as in a swiveling device for projection of records or films into specific solid angle areas. The prismatic joint can also be used in a swiveling device which is used as a monitoring or search device or, conversely, is also suitable for use as a 3D target simulator with a high-resolution target projection display. In particular, the prismatic joint is suitable for an optical swiveling device for target acquisition in a homing head of a guided missile.
Commonly assigned European patent EP 1 586 195 B1 (cf. U.S. patent publication US 2006/0243853 A1) discloses a prismatic joint for an optical swiveling device in a homing head of a guided missile, in which the prismatic joint comprises a number of first prisms which can rotate about a roll axis, and a number of second prisms which can rotate about a pitch axis with respect to the roll axis. The pitch axis and the roll axis in this case intersect at an angle of 90°. The first and second prisms can in this case each also be combined to form a single prism. The described prismatic joint comprises a total of four individual prisms which have side surfaces that are inclined at an angle of 45° to a base surface and of the same length. In one embodiment variant that is also disclosed, three of these prisms can in each case be combined to form one integral prism. A beam passing through the prismatic joint is deflected a total of four times by means of 90° total internal reflection on the inner faces of the side surfaces of the prisms, so that the optical image is independent of any rotation with respect to the roll axis and with respect to the pitch axis.